ESTROGEN RECEPTOR DETECTED IN THE FACIAL NUCLEUS OF NEWBORN RATS.

本文观察了新生大鼠脑内含雌激素受体（ER）神经元的分布和个体发生。含有ER的神经元分为两种类型，即，(1)成人型：（2）新生儿型：ER仅在胎儿至新生儿期短暂出现。成人型见于视前核、终纹床核、下丘脑弓状核、腹内侧核和室周核、中脑中央灰质、外侧缰核、杏仁核内侧核和皮质核。另一方面，新类型只出现在面神经核的腹内侧亚核和初级听皮层的第5层。雌激素给药降低ER免疫反应性在这两种类型的ER。ER mRNA的表达在这两种情况下，通过原位杂交检测。但前者的雄激素分泌区含有芳香化酶，表明雄激素已转化为雌二醇，而后者则没有。仅前一组存在性别差异。因此，前者（成年型）可能与脑的性别分化直接相关，而后者（新生型）可能与雌激素对发育中脑的刺激作用有关。通过逆行追踪、ER和胆碱乙酰转移酶双重免疫组化染色及电镜免疫细胞化学观察，提示新生期短暂含有ER的细胞为未成熟运动神经元。

Distribution and ontogeny of estrogen receptor (ER) -containing neurons in the newborn rat brain was examined. Neurons containing ER were classified into two types, i.e.,(1) Adult-type : the ER neurons appear in the same regions in the newborn as those in the adult ;(2) Newborn-type : the ER appears transiently only during the fetal to newborn period. The adult-type was observed in the preoptic nucleus, in the bed nucleus of the stria terminalis, in the hypothalamic arcuate, ventromedial and periventricular nuclei, in the midbrain central gray, in the lateral habenular nucleus, and medial and cortical nuclei of the amygdala. On the other hand, the newborn-type appears only in the ventromedial subnucleus of the facial nucleus and the layr 5 of the primary auditory cortex. Estrogen administration decreases ER immunoreactivity in the both types of ER.ER mRNA expression was detected by in situ hybridization in both cases. However, the area where former group was found contains aromatase immunoreactivity, which indicates androgen is converted to estradiol, while that for the latter does not. Sex difference was found only the former group. Thus, ER directly related to sex differentiation of the brain was suggested as the former (adult-type), while the latter (newborn-type) might be related to stimulating effects of estrogen in the developing brain. By retrograde track-tracing, double immunohistochemical staining of ER and choline acetyltransferase, and electron microscopic immunocytochemistry, the cells which contain ER transiently in the newborn life were suggested as immature motoneurons.